linux/drivers/pci/mmap.c

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// SPDX-License-Identifier: GPL-2.0
/*
* Generic PCI resource mmap helper
*
* Copyright © 2017 Amazon.com, Inc. or its affiliates.
*
* Author: David Woodhouse <dwmw2@infradead.org>
*/
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/pci.h>
#include "pci.h"
#ifdef ARCH_GENERIC_PCI_MMAP_RESOURCE
static const struct vm_operations_struct pci_phys_vm_ops = {
#ifdef CONFIG_HAVE_IOREMAP_PROT
.access = generic_access_phys,
#endif
};
int pci_mmap_resource_range(struct pci_dev *pdev, int bar,
struct vm_area_struct *vma,
enum pci_mmap_state mmap_state, int write_combine)
{
unsigned long size;
int ret;
size = ((pci_resource_len(pdev, bar) - 1) >> PAGE_SHIFT) + 1;
if (vma->vm_pgoff + vma_pages(vma) > size)
return -EINVAL;
if (write_combine)
vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
else
vma->vm_page_prot = pgprot_device(vma->vm_page_prot);
if (mmap_state == pci_mmap_io) {
ret = pci_iobar_pfn(pdev, bar, vma);
if (ret)
return ret;
} else
vma->vm_pgoff += (pci_resource_start(pdev, bar) >> PAGE_SHIFT);
vma->vm_ops = &pci_phys_vm_ops;
return io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
vma->vm_end - vma->vm_start,
vma->vm_page_prot);
}
#endif
#if (defined(CONFIG_SYSFS) || defined(CONFIG_PROC_FS)) && \
(defined(HAVE_PCI_MMAP) || defined(ARCH_GENERIC_PCI_MMAP_RESOURCE))
int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vma,
enum pci_mmap_api mmap_api)
{
resource_size_t pci_start = 0, pci_end;
unsigned long nr, start, size;
if (pci_resource_len(pdev, resno) == 0)
return 0;
nr = vma_pages(vma);
start = vma->vm_pgoff;
size = ((pci_resource_len(pdev, resno) - 1) >> PAGE_SHIFT) + 1;
if (mmap_api == PCI_MMAP_PROCFS) {
pci_resource_to_user(pdev, resno, &pdev->resource[resno],
&pci_start, &pci_end);
pci_start >>= PAGE_SHIFT;
}
if (start >= pci_start && start < pci_start + size &&
start + nr <= pci_start + size)
return 1;
return 0;
}
#endif